Open AccessAmplitude-modulated continuous-wave radar in the terahertz range using lock-in phase measurement
Author(s) -
Adrian Dobroiu,
Ryotaka Wakasugi,
Yusuke Shirakawa,
Safumi Suzuki,
Masahiro Asada
Publication year - 2020
Publication title -
measurement science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.48
H-Index - 136
eISSN - 1361-6501
pISSN - 0957-0233
DOI - 10.1088/1361-6501/ab912a
Subject(s) - terahertz radiation , oscilloscope , amplitude , radar , optics , quadrature (astronomy) , physics , acoustics , computer science , telecommunications , detector
We present the principle and the experimental verification of a distance measurement method based on the propagation of terahertz waves. The method relies on modulating the amplitude of a resonant-tunneling-diode (RTD) oscillator used as terahertz-wave source and on measuring the phase of the detected wave by applying a quadrature mixing technique. The distance measurement is found to have a residual error as small as 0.063 mm (standard deviation), which is a record for an RTD-based terahertz-wave radar system. This is almost five times better than our previous record of 0.29 mm, when an oscilloscope was used for phase measurements; additionally, the quadrature mixing brings about numerous practical benefits, such as greatly reduced cost, size, weight, complexity, and power consumption.